INSITU XPS CHARACTERIZATION OF TRIETHYLGALLIUM EXPOSED GAAS AND ALAS SURFACES

We studied adsorption, desorption, and decomposition of triethylgallium (TEG) on GaAs (100) and AlAs (100) surfaces in gas source molecular beam epitaxy. The adsorbed molecules were analyzed in situ with an X-ray photoelectron spectroscopy (XPS) system connected to the growth chamber via UHV chambers. We propose a model for TEG decomposition on the surface based on experimental results taken at substrate temperatures between room temperature and 600°C. At room temperature, 0.4 monolayer of TEG was observed molecularly. As the substrate temperature increased to 450 °C, the ethyl radicals decreased and the Ga increased. Above 450 °C, no carbon was observed within the detection limit of XPS, and all Ga atoms, which were introduced onto the surface as TEG, adsorbed on the surface. We also observed chemical shifts of the binding energy of Ga 3d and C1s emissions. © 1990.